The Change of Proximal Reference of Tibial Plateau in Total Knee Replacement: The Cadaveric Study

Nam, Woo Dong; Rhyu, Kee Hyung; Han, Kye Young

Abstract

PURPOSE: We frequently observed varus cutting of tibia in total knee arthroplasty. And we found that the extension of the tibial shaft axis often reach the lateral intercondylar eminence. So right tibias were osteotomized as usual manner and left tibias were osteotomized as the proximal reference point of cutting at the lateral intercondylar eminence, then we compared the differences.
MATERIALS AND METHODS
By using 6 cadavers, right tibias were osteotomized as usual manner and left tibias were osteotomized as the proximal reference point of cutting at the lateral intercondylar eminence. Tibial prosthesis were implanted after measuring the thickness of cut tibial condyles. The radiological examinations were accomplished pre- and postoperatively. With postoperative X-ray films, we measured the angles between the perpendicular line to the prosthesis and shaft axis/mechanical axis.
RESULTS
The mediolateral differences of cut tibial condyles were not statistically different between right and left tibias. The right angles between the perpendicular line to the prosthesis and shaft axis/mechanical axis were measured average varus 1.00 and 1.08 degree and left angles average varus 0.25 and 0.17 degree, so no statistical differences were observed(p=0.066, 0.066).
CONCLUSIONS
Although no statistical differences, we could get more stable alignment by valgus osteotomy and somewhat low incidences of varus cutting were observed. In the future more studies would be required by using varus deformed tibias.